D072101 0806 0108 E Capacity Control wo D9R Kapacitetsreglering.pdf · D7.21.01/0806-0108/E 7/27 Technical Information 2.4.3 D8SK-700X Diagram 5 Suction gas temperature 25°C 2.5

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Technical Information

Date of last update: 01-08 Ref: D7.21.01/0806-0108/E

Application Engineering Europe

DDWWMM CCOOPPEELLAANNDD SSEEMMII--HHEERRMMEETTIICC CCOOMMPPRREESSSSOORRSS CCAAPPAACCIITTYY CCOONNTTRROOLL

1 Compressor Capacity Modulation for Air Conditioning & Refrigeration Systems

1.1 Capacity ControlCompressors in the higher capacity range need some form of capacity control to accommodate varyingrefrigeration load. The capacity control kit supplied by DWM Copeland will reduce the refrigeration capacity alongwith a similar proportional reduction in Power Input. This ensures optimum performance even in part load.

Capacity control is also required when the condensing pressure falls with a drop in ambient air temperature.The compressor suction condition, refrigerant volume and mass flow rate will remain unchanged. The capacity willincrease due to the increase in h, along with the increase in volumetric efficiency, see the pH chart below.

1.2 Methods of Capacity Control

There are many methods of capacity control for Semi-Hermetic compressors but DWM Copeland use the “BlockedSuction method” and for the D3D Over Re-expansion method known as Moduload.

Note: Oil circulation in systems with capacity control is more critical

Advantages DisadvantagesReduces the starting frequency of the compressors Motor is less cooled (refrigerant flow reduced)Ensure satisfactory operation with optimal capacity data Restriction of the application rangeEnergy cost saving even at partial-load Oil circulation is more critical

Additional Capacity at lower cond. pressure

Compressor Capacity at design condition

Pre

ssur

e

kJ/kg

P

h h

Same Compressor inlet condition

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2 DWM Copeland Semi-Hermetic S Series Models Capacity Control

For 4S, 6S and 8S cylinder compressors a mechanical capacity control is available.Be aware that capacity controlled operation changes the application range of the compressor.

2.1 Capacity ControlThe 4S, 6S & 8S compressors have an internal capacity control, they work on the principle of blocking the suctiongas passage to two or more cylinders. They require the use of a special cylinder head and a control valve withsolenoid coil. These items may be ordered installed at the factory or in a kit form for later installation.

The suction port of the valve plate will be closed by a control piston (blocked suction). To prevent transport damagethe solenoid valve is supplied loose and the cylinder head is fitted with a shipping plate, therefore the shipping platewith gasket must be removed and the solenoid valve with new gasket mounted. Do not put the compressor intooperation with the shipping plate this could result in erratic operation of the control piston and inadequate coolingcapacity.

2.1.1 Inactive Capacity ControlThese compressors can be ordered with inactive capacity control. There is a gasket under the shipping plate thatallows operation on 100% capacity. To convert to active capacity control all that is needed is to fit the solenoidvalve with the active gasket instead of the shipping plate.

2.1.2 Normal Operation (Full load)When the solenoid coil is not energised the top of the unloader piston is vented to suction pressure allowing thepiston to be lifted by means of a spring. The compressor draws gas from all cylinders and reaches full coolingcapacity.

2.1.3 Capacity Controlled Operation (Part load)When the solenoid coil is energised the top of the unloader piston is forced down with discharge gas pressurethereby blocking the suction gas passage into the cylinders thus enabling the compressor to run with reducedcapacity.

2.1.4 Position of Capacity ControlD4S

50%

Active Inactive

Internal snorkel valve located here

Gasket - Cylinder head for capacity control – Internal view – External view

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D6S D6R, D6SK & D6SU D8S

Capacity control must be fitted in the following positions:

D4S 50% terminal box sideD6SK 1st step 33% terminal box sideD6SK 2nd step 66% lower cylinder head on discharge valve sideD6S 1st step 33% terminal box sideD6S 2nd step 66% upper cylinder head

D8S 1st step 25% lower cylinder head on terminal box sideD8S 2nd step 50% lower cylinder head on discharge valve side

Retrofit Kit includes: Voltages of the solenoid valve coil:

1 x Cylinder head for capacity control 24V D.C.1 x Gasket kit 24V / 1~ / 50 / 60 Hz1 x Solenoid valve assembly (No 703 RB 001) 208-240V / 1~ / 50 / 60 Hz2 x Mounting screws 120V / 1~ / 50 / 60 Hz

Protection class: IP 55 (evaluation according to IEC 34)

Selection of Capacity Control

D4S - D8S R 22

CompressorNumber of Cylinderswith Capacity Control

RemainingRefrigeration Capacity

% (average values)

RemainingPower Input

% (average values)Diagram No

H / M H / MD4SA-2000 2 100% 50% 51 53D4SH-2500 2 100% 50% 51 53D4SJ-3000 2 100% 50% 51 53D6SA-3000 2 / 4 100% 66% 33% 67/34 68/34D6SH-3500 2 / 4 100% 66% 33% 67/34 68/34D6SJ-4000 2 / 4 100% 66% 33% 67/34 68/34D8SH-5000 2 / 4 100% 75% 50% 76/53 79/57D8SJ-6000 2 / 4 100% 75% 50% 76/53 79/57D8SK-7000 2 / 4 100% 75% 50% 76/53 79/57 2B

Application limit: see data sheets and application diagramsH = high temperatureM = medium temperature

2A

D_T_SHC_029

Capacity RegulatingStep

Application Range

1

0 1 2

66 %

66 %33 % 33 %

25 %50 %

310 310

610

295

Optional50%

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2.2 Application Range – R22

2.2.1 D4SA / H / J & D6SA / H / JDiagram 1 Suction gas temperature 25 °C

2.2.2 D8SH / JDiagram 2A Suction gas temperature 25°C

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2.2.3 D8SK – 7000Diagram 2B Suction gas temperature 25°C

2.3 Selection of Capacity Control

D4S - D8S R 407C (mid-point)



% (average values)


% (average values)Diagram No

H / M H / MD4SA-200X 2 100% 50% 51 53D4SH-250X 2 100% 50% 51 53D4SJ-300X 2 100% 50% 51 53D6SA-300X 2 / 4 100% 66% 33% 67/34 68/34D6SH-350X 2 / 4 100% 66% 33% 67/34 68/34D6SJ-400X 2 / 4 100% 66% 33% 67/34 68/34D8SH-500X 2 / 4 100% 75% 50% 76/53 79/57 4D8SJ-600X 2 / 4 100% 75% 50% 76/53 79/57D8SK-700X 2 / 4 100% 75% 50% 76/53 79/57 5

Application limit: see data sheets and application diagramsH = high temperatureM = medium temperature D_T_SHC_030

3


0 1 2Application Range

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2.4 Application Range – R407C mid-point

2.4.1 D4SA / H / J & D6SA / H / J

Diagram 3 Suction gas temperature 25°C

2.4.2 D8SH / JDiagram 4 Suction gas temperature 25°C

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2.4.3 D8SK-700XDiagram 5 Suction gas temperature 25°C

2.5 Selection of Capacity Control

D4S - D8S R 404A


Diagram No

H M L H M LD4SF-100X 2 100% 50% 52 59D4SL-150X 2 100% 50% 52 59D4ST-200X 2 100% 50% 52 59D4SA-200X 2 100% 50% 51 52 53 59D4SH-250X 2 100% 50% 51 52 53 59D4SJ-300X 2 100% 50% 51 52 53 59D6SF-200X 2 / 4 100% 66% 33% 68/34 70/41D6SL-250X 2 / 4 100% 66% 33% 68/34 70/41D6ST-320X 2 / 4 100% 66% 33% 68/34 70/41D6SU-400X 2 / 4 100% 66% 33% 68/34 70/41D6SA-300X 2 / 4 100% 66% 33% 67/34 68/34 68/36 70/41D6SH-350X 2 / 4 100% 66% 33% 67/34 68/34 68/36 70/41D6SJ-400X 2 / 4 100% 66% 33% 67/34 68/34 68/36 70/41D8SH-370X 2 / 4 100% 75% 50% 76/53 76/53 79/56 80/58D8SJ-450X 2 / 4 100% 75% 50% 76/53 76/53 79/56 80/58D8SH-500X 2 / 4 100% 75% 50% 76/53 76/53 79/56 80/58D8SJ-600X 2 / 4 100% 75% 50% 76/53 76/53 79/56 80/58

Application limit: see data sheets and application diagrams

H = high temperatureM = medium temperatureL = low temperature

6 & 7

0 1

D_T_SHC_031

Capacity RegulatingSteps


% (average values)


% (average values)

8 & 9

6 & 7

8 & 9

2Application Range

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2.6 Application Range - R404A

2.6.1 D4SF / L / T & D6SF / L / T / UDiagram 6: Suction gas temperature 25°C

Low Temperature WITH Additional Cooling (Fan)

Diagram 7: Suction gas temperature 25°CLow Temperature WITHOUT Additional Cooling (Fan)

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2.6.2 D4SA / H / J & D6SA / H / J & D8SH / JDiagram 8: Suction gas temperature 25°C

Medium Temperature WITH Additional Cooling (Fan)

Diagram 9 Suction gas temperature 25°CMedium Temperature WITHOUT Additional Cooling (Fan)

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3 DWM Copeland Semi-Hermetic Discus Models Capacity Control

All Discus model compressors can be equipped with capacity control. When the compressor is operated usingcapacity control the application range changes.

To prevent transport damage the solenoid valves are supplied loose with the compressor, and the cylinder head isfitted with a shipping plate. The shipping plate and the gasket must be removed. Then the solenoid valve must bemounted using the gasket supplied. Torque to 58-69 Nm.

A retrofit kit is available. The kit does not contain the valve-plate to body gasket. This must be ordered separately.The gasket thickness is marked on the gasket itself (“X”). When ordering please state refrigerant.For conversion kits see spare parts list, the kit contains mounting instructions and a complete bill of material.

3.1 Moduload for D3D CompressorsModuload is an efficient capacity control based on the principle of adjustable clearance volume. The capacitycontrol kit will reduce both the refrigeration capacity and the power input in almost the same proportion, whichensures optimum performance even in part load.The solenoid valve may be energized by a thermostat, a pressure control switch or a multiple contact switch.When the solenoid valve is energized the three control pistons are loaded with the evaporator pressure via theopened connection to the suction side. The spring power pushes the three control pistons upwards, thus increasingthe clearance volume.

There are two different versions of Moduload:1. Suitable for HFC refrigerants R404A/R507 and R134a with the relevant refrigerant oils approved by

COPELAND.;2. Suitable for R22 and for the approved refrigerant oilsMODULOAD should not be fitted on compressors with DEMAND COOLING.

A full-load operation B part load operation

1 Solenoid coil 2 Control piston 3 Cylinder head 4 Valve plate 5 Compressor body 6 piston

7

1

3

4

2

56

A B

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3.2 D3D Capacity Control Selection Tables for Moduload

Voltages of the solenoid valve coil:24 V D.C.24 V / 1~ / 50 Hz120 V / 1~ / 50 / 60 Hz208-240 V / 1~ / 50 / 60 Hzprotection class: IP 55 (evaluation according to IEC 34)

The diagrams show the application range while operating with capacity control, remaining refrigerantcapacity and power input at 25oC suction gas temperature.

Cooling capacity (part load) = cooling capacity (full load) x factor

Power input (part load) = power input (full load) x factor

Tentative Data

90

Compressor with Refrigerant Range Diagram Compressor with Refrigerant Range DiagramMODULOAD MODULOADD3DA*-50XH R 134a HM 1 D3DA*-50X L R404A LXZ 4D3DC*-75XH D3DC*-75X LD3DS*-100XH D3DS*-100X LD3DA*-75XH R 134a HH 2 D3DA*-750H R 22 HM 5D3DC*-100XH D3DC*-1000HD3DS*-150XH D3DS*-1500HD3DA*-75XH R 404A HM 3D3DC*-100XHD3DS*-150XH

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3.2.1 D3D Moduload R134a HM Part-load Factors

The diagrams show the application range while operating with capacity control, remaining refrigerant capacity andpower input at 25oC suction gas temperature.

Diagram 1

Power Input %

Co

olin

gC

apac

ity

%

20

40

60

80

20 30 40 50 60 70 80 90 100

Example

Evaporating Temperature 0C

Co

olin

gC

apac

ity

%

Co

nd

ensi

ng

Tem

per

atu

re0 C

20

40

60

80

30

35

40

45

50

55

60

-15 -10 -5 0 5 10 12.5

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3.2.2 D3D Moduload R134a HH Part-load Factors

Diagram 2

Power Input %

Co

olin

gC

apac

ity

%

80

60

40

20

20 30 40 50 60 70 80 90 100

Example

Evaporating Temperature °C

Co

olin

gC

apac

ity

%

Co

nd

ensi

ng

Tem

per

atu

re0 C

-10 -5 0 5 10 15 20 25

20

40

60

80 40 50

60

70

80

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3.2.3 D3D Moduload R404A HM Part-load Factors

Diagram 3

Power Input %

Co

olin

gC

apac

ity

%

20 30 40 50 60 70 80 90 100

20

40

60

80

Example


Co

nd

ensi

ng

°C

Co

olin

gC

apac

ity

%

-20 -15 -10 -5 0 5 7.5

20

40

60

80 3035

40

45

50

55

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3.2.4 D3D Moduload R404A LXZ Part-load Factors

Diagram 4

Power Input %

Co

olin

gC

apac

ity

%

20 30 40 50 60 70 80 90 100

20

40

60

80

ExampleEvaporating Temperature °C

Co

olin

gC

apac

ity

%

Co

nd

ensi

ng

°C3035404550

55

-40 -35 -30 -25 -20

20

40

60

80

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3.2.5 D3D Moduload R22 HM Part-load FactorsDiagram 5

Power Input %

Co

olin

gC

apac

ity

%

20 30 40 50 60 70 80 90 100

20

40

60

80

Example


Co

olin

gC

apac

ity

%

Co

nd

ensi

ng

°C30

50

55

60

35

45

40

-15 -10 -5 0 5 10 12.5

20

40

60

80

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4 Capacity Control D4D, D6D and D8D Compressors

Capacity-controlled D4D, D6D, and D8D compressors work on the principle of blocking the suction gas passage totwo or more cylinders. They require the use of a special cylinder head, a control valve with solenoid coil, and in thecase of Discus a special valve plate, too. These items may be ordered installed at the factory or in kit form for laterinstallation.

Normal Operation Full Load: When the solenoid coil is not energised the top of the control piston is vented tosuction pressure allowing the piston to be lifted by means of a spring. The compressor draws gas from all cylindersand reaches full cooling capacity.

Capacity Controlled Operation (Part Load): When the solenoid coil is energised the top of the control piston isforced down by gas at discharge pressure blocking the suction gas passage into the cylinders thus enabling thecompressor to run with a reduced capacity.

Normal Operation (Full Load) Unloaded Operation (Part Load)valve de-energized suction port open valve energized-suction port closed

Voltages of the solenoid valve coil:24 V D.C.24 V / 1~ / 50 Hz120 V / 1~ / 50 / 60 Hz208-240 V / 1~ / 50 / 60 Hzprotection class: IP 55 (evaluation according to IEC 34)

4.1 Capacity Controlled Cylinder Head Gaskets for 4, 6 & 8 Semi-Hermetic CompressorsAll capacity control prepared cylinder heads on 4, 6 and 8 cylinder semi-hermetic compressors are delivered withthe mounted inactive gasket for the capacity controlled port, this will ensure full capacity operation of thecompressor if the solenoid control valve is not installed for any reason. To activate the capacity control, the blindflange and the inactive gasket have to be removed and to be replaced by the solenoid control valve and the activegasket which is provided with the conversion kit.

The gasket change was effective with compressors shipped from our Welkenraedt, Belgium plant from August17,1999

Conversion kit includes;

1 x cylinder head for capacity control “C”

Valve plate

Dischargepressure

Solenoid valve

Spring

Controlpiston

Suctionpressure

Cylinder head

Top of piston discharging through valve plate

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1 x valve plate and gasket kit1 x solenoid valve assembly2 x mounting screws

Capacity control must be fitted in the following positions:

D4D 50% terminal box side

D6D 1st step 33% terminal box sideD6D 2nd step 66% upper cylinder headD8D 1st step 25% lower cylinder head on terminal box sideD8D 2nd step 50% lower cylinder head on discharge valve side

25%50%

33%

50%

Optional 50%

66%

written “C” for capacity controlD6D_3/4/5 D8D_1/5

C

C

D4D 3/4/5

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4.2 R134a Capacity Control Selection Table

D4D - D8D

CompressorNo.Cylinders

with Cap.Con.Diagram No

HH H M L HH H M LD4DA-100X 2 100% 50% 51 52 53 59 8D4DH-150X 2 100% 50% 51 52 53 59 8D4DA-200X 2 100% 50% 51 53 9D4DJ-200X 2 100% 50% 51 52 53 59 8D4DH-250X 2 100% 50% 51 53 9D4DJ-300X 2 100% 50% 51 53 9D6DH-200X 2 / 4 100% 66% 33% 67/34 68/34 68/36 70/41 8D6DJ-300X 2 / 4 100% 66% 33% 67/34 68/34 68/36 70/41 8D6DH-350X 2 / 4 100% 66% 33% 67/34 68/36 9D6DJ-400X 2 / 4 100% 66% 33% 67/34 68/36 9D8DH-500X 2 / 4 100% 75% 50% 75/51 75/51 75/52 77/53 77/53 78/59 8(HM) /10(HH)D8DJ-600X 2 / 4 100% 75% 50% 75/51 75/51 75/52 77/53 77/53 78/59 8(HM) /10(HH)

Application lim it see data sheets and application diagrams

HH = heat pumpH = highM = mediumL = low temperature

Application Range0 1 2

Remaining Refrigeration Capacity / Power Input(average values) %


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4.3 R134a Application Range

4.3.1 D4D – D8DDiagram 8Suction gas temperature 25°C

Diagram 9Superheat 20 K

Diagram 10

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Superheat 20 K

4.4 R22 Capacity Control Selection Table

D4D - D8D


Diagram No

H HD4DA-2000 2 100% 50% 51 53D4DH-2500 2 100% 50% 51 53D4DJ-3000 2 100% 50% 51 53D6DH-3500 2 / 4 100% 66% 33% 67/34 68/34D6DJ-4000 2 / 4 100% 66% 33% 67/34 68/34D8DH-5000 2 / 4 100% 75% 50% 76/52 80/58D8DJ-6000 2 / 4 100% 75% 50% 76/52 79/57

Application limit see data sheets and application diagrams

H = high

0 1

Remaining Refrigeration Capacity / PowerInput (average values) %


12

2Application Range

11

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4.5 R22 Application Range

4.5.1 D4D – D8D



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4.6 R404A Capacity Control Selection Table

4.7 R404A Application Range

4.7.1 D4D – D8DDiagram 13Suction gas temperature 25°C

D4D - D8D


Diagram No

HH H M L HH H M LD4DF-100X 2 100% 50% 52 59 13D4DL-150X 2 100% 50% 52 59 13D4DA-200X 2 100% 50% 51 52 53 59 15D4DT-220X 2 100% 50% 52 59 13D4DH-250X 2 100% 50% 51 52 53 59 15D4DJ-300X 2 100% 50% 51 52 53 59 15D6DL-270X 2 100% 66% 68 70 13D6DT-300X 2 100% 66% 68 70 13D6DH-350X 2 / 4 100% 66% 33% 67/34 68/34 68/36 70/41 16D6DJ-400X 2 / 4 100% 66% 33% 67/34 68/34 68/36 70/41 16D8DL-370X 2 100% 75% 77 78 14D8DT-450X 2 100% 75% 77 78 14D8DH-500X 2 / 4 100% 75% 50% 76/52 76/52 79/56 80/58 17D8DJ-600X 2 / 4 100% 75% 50% 76/53 76/53 79/56 80/58 17


HH = heat pumpH = highM = mediumL = low temperature

Application Range

Capacity RegulatingSteps

0 1

Remaining Refrigeration Capacity / Power Input

2

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Diagram 14Suction gas temperature 25°C

Diagram 15Suction gas temperature 25°C

Diagram 16 Suction gas temperature 25°C Reduction to 33% with standard additional Ventilation not possible dueto lack of space

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4.8 R407C (mid-point) Capacity Control Selection Table

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4.9 R407C (mid-point) Application Range

4.9.1 D4D – D6D

Diagram 18 Suction gas temperature 25° C

4.9.2 D8D

Diagram 19 Suction gas temperature 25° C

Evaporating [OC]

Con

dens

ing

[OC

]

15

20

25

30

35

40

45

50

55

60

65

-30 -25 -20 -15 -10 -5 0 5 10 15

100%

66%

50%

33%

D4D - D8D


Diagram No

H HD4DA-200X 2 100% 50% 51 53D4DH-250X 2 100% 50% 51 53D4DJ-300X 2 100% 50% 51 53D6DH-350X 2 / 4 100% 66% 33% 67/34 68/34D6DJ-400X 2 / 4 100% 66% 33% 67/34 68/34D8DH-500X 2 / 4 100% 75% 50% 76/52 80/58D8DJ-600X 2 / 4 100% 75% 50% 76/53 79/57


H = high

0 1

Remaining Refrigeration Capacity / PowerInput (average values) %


19

2Application Range

18

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15

20

25

30

35

40

45

50

55

60

65

-30 -25 -20 -15 -10 -5 0 5 10 15

100%

50%

75%

Con

dens

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[OC

]

Evaporating °C

Documents

D072101 0806 0108 E Capacity Control wo D9R Kapacitetsreglering.pdf · D7.21.01/0806-0108/E 7/27 Technical Information 2.4.3 D8SK-700X Diagram 5 Suction gas temperature 25°C 2.5